Our aim is to understand the structural relationship between TLR5 human homolog, TLR11 mouse homolog and their respective ligands. The human TLR5 recognizes flagellin whereas TLR11 recognizes a structural protein profilin. The biochemical aspects of these interactions are well understood. An initial attempt in expressing hTLR5 and mTLR11 by themselves in a baculovirus system was unsuccessful. The proteins were either degraded overtime or driven into inclusion bodies. Even under these conditions, small quantities of TLR5 were isolated from the cell pellet as a soluble protein. The extracted hTLR5 protein has shown to be glycosylated and the N-terminal signal peptide has been processed. However, the insect cellular system is unable to export the protein. Since then we have been able to express and purify the hTLR5/Flagellin as a soluble complex in a prokaryotic expression system in large quantities. [unreadable] [unreadable] mTLR11 ectodomain has been expressed and purified in a baculovirus system. In this expression system chaperones were used for increasing expression of mTLR11. Using this method mTLR11 protein has been expressed in significant quantities. The down side of this co-expression is that mTLR11 seems to be interacting with the chaperones until the last steps of purification. The purification conditions for both hTLR5 and mTLR11 proteins are currently being optimized.